Water-insoluble monoazo dyestuffs



United States Patent 3,393,190 WATER-INSOLUBLE MON OAZO DYESTUFFS Paul L. Stright, Hamburg, N.Y., assignor to Allied Chemical Corporation, New York, N.Y., a corporation of New York No Drawing. Filed Apr. 7, 1965, Ser. No. 446,379 9 Claims. (Cl. 260-155) ABSTRACT OF THE DISCLOSURE Water insoluble monoazo dyestuffs derived by coupling a diazotized Z-aminopyridine-l-oxide with a 2,4dihydroxyquinoline or a compound containing the radical --CH CO which are 1,3-diketones or pyrazolones, capable of undergoing keto-enol tautomerism and free of water-solubilizing groups; the dyestuffs of the present invention are useful for dyeing metal-containing polymers of alpha olefins having 2-4 carbon atoms, particularly polypropylene.

The present invention relates to the process of dyeing metal-containing polyolefins with metallizable monoazo dyestuffs derived from diazotized Z-aminopyridine-loxides. It further relates to novel, metallizable, monoazo dyestuffs which are derived by coupling diazotized 2- aminopyridine-l-oxides with a coupling component containing an active methylene group.

It is known that polyolefin fibers have poor dyeing properties due to chemical inertness and the absence of receptive sites. Numerous techniques have been devised to circumvent this difficulty with varying degrees of success, but none has proved entirely satisfactory. A more successful technique, disclosed in my co-pending application, Ser. No. 261,858, filed Feb. 28, 1963, and now US. Patent No. 3,254,072, involves the application to metalcontaining polypropylene of 2 (8-quinolylazo)-1,3-diketones, which are capable of forming Werner type complexes with many metals. Although, as described in said co-pending application, these quinolylazo dyes are generally suitable for the coloration of olefinic polymers containing metals such as nickel, zinc, cobalt, copper, cadmium, titanium, aluminum, iron, zirconium, maganese, vanadium and the like transition group of elements, some are lacking in certain desirable dyeing properties, i.e., uniformity, compatibility and penetration.

According to the present invention, it has now been found that metallizable water-insoluble monoazo dyestuffs of the disperse type, which are obtained by diazotizing 2- aminopyridine-l-oxides and coupling the same with suitable compounds containing at least one group capable of forming a chelate with a metal, possess excellent dyeing characteristics for metal-containing polymers of u-olefins having 24 carbon atoms, particularly polypropylene. Suitable coupling compounds include, for example, phenols, naphthols, 1,3-diketones, pyrazolones and quinolines which are free of water-solubilizing substituents. Piece goods of polypropylene fibers containing metal are dyed with the above-described dyestuffs in deep level shades having excellent fastness to light, washing, dry cleaning, cracking, ozone, oxides of nitrogen, sublimation and chlo- The novel dyestuffs of my invention are water-insoluble monoazopyridine-l-oxides conforming to the general formula:

wherein A represents a pyridine-l-oxide residue and C represents the residue of a coupling component which is a 2,4-dihydroxyquinoline or a compound containing the radical --CH CO. Coupling components of the latter class are more specifically identified as compounds ice capable of undergoing keto-enol tautomerism. Examples of keto-enolizable compounds suitable for use in preparing the novel dyestuffs of the present invention include 1,3-diketones and pyrazolones which are free of Watersolubilizing substituents. It is highly probable that ketoenol tautomerism characteristics of such compounds 'play an important role in the metallization of the dyes of this invention containing the same when applied to metal-containing polyolefins.

The preferred pyridine-l-oxide residue may be represented by the general formula:

wherein R represents a lower alkyl or alkoxy group containing 1-6 carbon atoms, halogen or nitro; and n is an integer of 03.

The novel dyestuffs of the present invention can be prepared by the conventional methods of preparing monoazo dyestuffs. In accordance with the well known practices in this art, a Z-a-minopyridine-l-oxide of the class described above is diazotized with nitrous acid and the diazonium salt solution is coupled in a weakly alkaline medium with the coupling component. The resultant monoazo coupling product is generally insoluble in the coupling mixture, from which the coupling product can be isolated in any suitable manner, e.g., by filtration or centrifugation. The isolated product can be purified, if desired, by reslurrying in slightly acidified Water. The monoazo compounds are generally ground in the presence of dispersing agents in a conventional manner to obtain a satisfactory dyestuff composition dispersible in water.

Examples of Z-aminopyridine-l-oxides useful in the preparation of the dyestuffs of this invention are:

2-aminopyridine-1-oxide 2-amino-3-methylpyridinel-oxide 2-amino-5-ethoxypyridinel-oxide 2-amino-4-methylpyridinel-oxide 2-amino-6-methylpyridine-1 -oxide 2-amino-4,6-dimethylpyridine- 1 -0Xide 2-amino-3,5-dib romopyridinel-oxide 2-amino-4-n-butylpyridinel-oxide Z-amino-S-n-butoxypyridinel-oxide 2-amino-4-ethyl-6-methylpyridinel-oxide Z-amino-S-n-hexyl-3-methylpyridine-l-oxide 2-amino-4-nitropyridine-l-oxide Examples of coupling components suitable for the preparation of the novel dyes of my invention are:

2,4-pentanedione l-phenyl-1,3-butanedione 1-(4-chlorophenyl)41,3-butanedione 1,3 -diphenyl-1,3-propanedione l,3-bis(2-chloro-4-methylphenyl)-l,3-propanedione 1,1 l-trifluoro-2,4-pentanedione 1,1 ,l-trifluoro-4-(2-thienyl) -2,4-butanedione 1-(2-furyl)41,3-butanedione 1,3 -cyclohexanedione 5,5 -dimethyl-1,3-cyclohexanedione 4-benzoyl-1,3-cyclohexanedione acetoacetylaminobenzene benzoylacetylaminobenzene acetoacetyl-Z-aminonap-hthalene 2-ethoxy- 1-acetoacetyl-aminobenzene 4-methoxy-l-acetoacetylaminobenzene 2-ethoxy-4-trifluoromethyl 1-acetoacetylaminobenzene Z-ethoxy-S-rnethyll-aceto acetylaminobenzene Z-cyanol-acetoacetyl aminobenzene 2-bromo-6-methyl-1-acetoacetylaminobenzene 2,4-dimethyl-l-aoetoacetylaminobenzene 2-ethoxy-4-bromo-5-methyl-1=acetoacetylaminobenzene 2-ethoxy-4-chloro-6-methyl-1-acetoacetylaminobenzene 2-methoxy-4-trifiuoromethyll -acet o acetyl aminobenzene 2,4-dihydroxyquinoline 2,4-dihydroxy-G-methyl-quinoline 2,4-dihydroxy-8 chloro-quinoline 2,4-dihydroxy-6-methoxy-quinoline 6-bromo-2,4- dihyd-roxy-quinoline 7-chloro-2,4-dihydroxy-S-methyl-quinoline 3-methyll -phenyl-2 pyrazolin--one l-(m-chlorophenyl) -3-methyl-2-pyrazolin-5 -one 1-( 5 -bromo-3 -pyridyl) -3-methyl-2-pyrazolin-5-one 1-( 2-benzothiazolyl) 3 -methyl-2-pyrazolin-5one 1- p-ethoxyphenyl -3-methyl-2-pyrazolin-5 -one 1- ('p-tolyl) -3-methyl-2-pyrazolin-5-one 1- (m-nitrophenyl) -3 -methyl-2-pyr-az olin-5 -one 3 -methyl-1-(2,4, 6-trichlorophenyl) -2-pyrazolin-5 -one barbituric acid Additional specific examples of metallizable :monoazo dyestufls of the disperse type derived from diazotized 2- aminopyridine-l-oxides which may be employed in the process of dyeing metal-containing polyolefins in accordance with the present invention include the following:

2- (2,4-dihydroxy-1-phenylazo -pyridine-1oxide 2-(5-benzoyl-2,4-dihydroxy-l-pheny1azo)pyridine-1- oxide 2- Z-anilinol -n aphthylazo -pyridine-1-oxide 2-[ (4-hydroxy-m-tolyl) azo]-pyridine-l-oxide 1 2- (S-acetamido-Z-hydroxyl-naphthylazo pyridine-1- oxide 2-( 4,6-diamino-3-to-lylazo -pyridinel-oxide 2- (2-hydroxyl -naphthylazo) -3 -methylpyridinel-oxide 2-(2-hydroxy-1-naphthylazo) -4-methylpyridine- 1-oxide 2-(2-hydroxy-l-naphthylazo -6-methylpyridine-1-oxide 2-(2-hydroxy-1-naphthylazo -4, 6-dimethylpyridine-1- oxide Dyestuffs suitable for use in dyeing a-olefins in accordance with this invention are substantially insoluble in water, and are applied in a conventional manner for disperse dyes. A dispersion of the unmet-allized dyestutf, which is in a finely divided state, is added to the aqueous dyebath, maintained at a pH of 3-5, which contains the polyolefin material, dispersing agents and other dyeing adjuvants. Such variables as temperature, dyeing time and concentration of dye are controlled to obtain the desired depth of shape. Although temperatures ranging from 50 C. to the boiling point of the bath may be used, I prefer to operate in the range of 80-95 C. Residence time is not critical and 1 /2 to 2 hours are generally sufiicient. Dye concentrations generally employed may vary widely depending upon the depth of shade desired. Light shades are obtainable with as little as 0.001% of dye, based on the weight of the material while deep shades can be obtained by the use of about 0:1 to 0.3% of pure dye.

The dyestufis employed for dyeing metal-containing polypropylene by this invention display, surprisingly, improved dyeing behavior, for example, compared with previously mentioned known dyes derived from 8-amino= quinoline and active methylene group coupling components, since presumably, they both are fixed to the fiber by chelation. It is not intended that this invention be limited to any theory of action. However, we believe that a plausible explanation may lie in the difierence in temperature at which the two types chelate. The azoquinolinyl dyes build up slowly until the chelation temperature (about 60 C.) is reached, then the buildup of the metallized shade becomes rapid. This often results in poor penetration and surface coloration. The azopyridinel-oxide dyes, on the one band, do not appear to Example 1 2-[ (3-methyl-5-oxo-1-phenyl-2-pyrazol1n-4-yl) -azo pyridined-oxide A solution of 11.0 g. (0J1 mole) of 2-aminopyridinel-oxide in 25 ml. of 20 B. hydrochloric acid and 600 ml. of water is cooled to 0 C., and 50 ml. of a 2 molar aqueous solution of sodium nitrite is added over a period of about 15 minutes with agitation, The agitation is continued tor one hour after which a clear reddish yellow solution is obtained. The diazonium salt solution is then added to a solution of 17.6 g. (0.102 mole) of 3-methyl- 1 phenyl-Z-pyrazolin-S-one and 40 g. of sodium carbonate in 1 liter of water, over a period of 40 minutes, while maintaining the temperature between 5 and 10 C. The solid product is filtered and washed free of coupler. It is purified further by slurrying in water, acidifying to Delta paper and again filtering and washing with water. The product is obtained as a yellow solid, melting at 195- 197 C.

Example 2 Piece goods of nickel-containing polypropylene fiber are scoured, using 0.2% Triton X400 and 0.2% soda ash, for 10 min. at C. They are then placed in a bath set at 35 C. containing 1% Triton X-l00 (based on weight of fiber) and 1.0- 1.'5% formic acid (pH 3-4) and run for 5 minutes. A 1% (on wt. of fiber) dispersion of the dye from Example 1 is prepared in warm water and added to the dye bath. After 5 minutes, the temperature is raised to over a 30 min. period. The dyeing is continued at 95 C. for an additional 45 minutes. The piece goods are removed from the dye bath, rinsed, and soaped in 0.5% soap solution at 90 for 10 minutes, rinsed with water and dried. The resulting dyed piece goods are colored a deep yellow shade having excellent fastness to light, dry-cleaning, washing and crockmg.

Example 3 2- a- (o-methoxyphenylcarbamoyl acetonyl-azo] pyridine-l-oxlde A cold (05 C.) solution containing 0.1 mole of 2- pyridine-l-oxide diazonium chloride, prepared as described in Example 1, is added to a cold, agitated solutionconsisting of 21.1 g. (0.102 mole) of acetoacet-oanisidine, 30.0 g. (0.282 mole) of sodium carbonate, 10 ml. (0.192 mole) of 50 B. sodium hydroxide solution, and 500 ml. of water, over a 3 /2 hour period. The temperature is allowed to rise 25 C. and the mixture is stirred for 16 hours. The product is collected on a filter and Washed with 2 liters of a 10% salt solution containing 0.5% sodium hydroxide. The cake is then slurried with one 1. of 60 C. Water for 2 hours and then acidified wherein R represents a substituent selected from the group with 10% hydrochloric acid. Agitation is continued for 8 consisting of lower alkyl, lower alkoxy, halogen and hours at 60 C., then the product is filtered, washed with nitro; n is an integer of to 3 and C represents the water and dried. residue of a coupling component selected from the group The product of this example, when applied to metalconsisting of 2,4-dihydroxyquinolines and compounds containing polypropylene in accordance with the procontaining the radical CH CO which are 1,3-dikecedure described in Example 2, provides excellent penetones or pyrazolones, capable of undergoing keto-enol tration and dyes the polypropylene in yellow shades havtautomersion and free of water solnbizing substituents. ing good levelness, moderate light fastness hrs.) and T c dyestufis of claim 2 wherein n is 0 and C is excellent fastness to washing and dry-cleaning. 10 a 1-ary13-lower alkyl-2-pyraZolin-5-one.

4. The dyestuffs of claim 2 wherein n is 0 and C is a 1,3-lower alkane dione. 0 0H 5. The dyestuffs of claim 2 wherein n is 0 and C is a 2,4-dihydroxyquinoline. If --N=N 6. The dyestuif of the formula: it go JV N N 2 (2,4 dihydroxy-3-quino1ylazo -pyr1dine-1-oxide Example 4 2 0:0 N A cold solution o-s 0. containing 0.1 mole of the 0 1 (Lem diazonium salt described in Example 1, is added while it Ill stirring to a cold solution containing 19.52 g. (0.102 mole) of 2,4-dihydroxyquinoline, 30.0 g. (0.282 mole) of sodium carbonate, 10 ml. (0.192 mole) of 50 B. sodium hydroxide solution and 500 ml. of water over a period of 2.5 hours. The mixture is stirred at room tem- 7. The dyestutf of the formula:

perature. The product is isolated, washed and treated as described in Example 2. When applied to metal-containing polypropylene as de- 0118f I J scribed in Example 2, the product demonstrates excellent gpenetration and produces deep orange shades having excellent levelness. The dyeings exhibit outstanding fastness 0 to washing and dry-cleaning, and moderate light fastness a 8. The dyestuif of the formula:

The following tabulation further illustrates the monoazo compounds of my invention and sets forth the colors the nonmetallized compounds yield on metal-containing CH polypropylene. The dyestuffs were prepared in accord- OCH3 ance with the procedure of Example 1. The dyeings on l metal-containing polypropylene were carried out in act 0= cordance with the procedure of Example 2. O

Amine Used for Diazo Component Coupler Product Shade Z-amjnopyridineboxide 2, 4-pentanedione 2-(2,4-di0xd3-pentylazo)-pyridine 1-oxide Yell w. Do lmethyl-l,3-cyc10hexane- 2-[(1,3-dioXO-5,fi-dimethyl-2-cyclohexyl)azo]-pyridj11e-1- xide Doone. Q-amino-flmethylpyridine-l-oxide 3-methy1-1-pheny1-2-pyrazo 2-[ (3:methyl-5-oxo-1-phenyl-2-pyrazolin-4-y1)azo]-3-methylpyr- Reddish yellow.

' -5one. idane-l-oxide.

Z-amino--methylpyridinel-oxide d0 2-[(3-n net hyl-5-oxo-1-phenyl'2-pyrazo1in-4-yl) azo]-4-methyl- Do.

pyridine-l-oxide. z-amino-emethylpyridine-l-oxide ..d0 2-l(ii-me hy1-5-0X0-1-phenyl-2-pyrazo1in-4-y1)azo]-6-methy1- Medium reddish pyridine-l-oxide. ye 0w. 2-amjno4,6-dimetl1y1pyndm9-1- ....-d0 2-1( Ipethykioxdl-phenyl-2-pyrazo1in-4-y1)azo]-i,rdimethy1- Dark reddish oxide. pyndine-Loxide. yellow z-ami opyfl B Naphth01 Y OXY-l-naphthylazo)-pyridine-1-oxide vio1et Do p-Cresol (2-hyd '0Xy-4-methylphenylazo)-pyridine-1-oxide Grey.

I claim: 9. The dyestnff of the formula: 1. Water-insoluble monoazo dyestuffs of the formula:

A-N=NC OH wherein A is a pyridine -1-ox1de residue and C is the l .residue of a coupling component selected from the group consisting of 2,4-dihydroxyquinolines and compounds con- \N taining the radical CH CO which are 1,3-diketones or pyrazolones, capable of undergoing keto-enol tautomerism and free of Water solubilizing substituents.

2. Water-insoluble monoazo dyestuffs of the formula: References Cited FOREIGN PATENTS RD N N 0 642,346 1/1964 Belgium.

FLOYD D. HIGEL, Primary Examiner. 

